Process for producing TiO2 based photocatalytic coating, the TiO2 photocatalytic coating obtained by the process, and articles with TiO2 based photocatalytic coating applied thereon

Abstract

A water soluble photocatalytic material capable of being adhered to an article by a conventional coating process is described. The photocatalytic material includes a doped metal oxide substrate capable of exhibiting photocatalytic behavior on being exposed to visible light, wherein particle size of doped metal oxide substrate ranges from about 18 nanometer (nm) to about 35 nm. Further, the photocatalytic material includes a polymeric adhesive for improving the adhering property of the doped metal oxide substrate on the article. In addition, a process for producing the water soluble photocatalytic material is described. Further, an air purifying article, such as a sheet, on which the said photocatalytic material is applied to is also described.

I claim: 
     
       1. A water soluble photocatalytic material capable of being adhered to an article by a coating process, the water soluble photocatalytic material comprising:
 a) a doped TiO 2  substrate capable of exhibiting photocatalytic behavior on being exposed to visible light, the doped TiO 2  substrate being in a form of TiO 2  nano rods; and 
 b) a polymeric adhesive that enhances an adhering property of the water soluble photocatalytic material capable of being adhered to the article, wherein the polymeric adhesive comprises:
 an acrylic copolymer added in an amount in a range of about 55 percent by weight to about 65 percent by weight, 
 calcium carbonate added in an amount in a range of about 25 percent by weight to about 40 percent by weight, and 
 propylene glycol added in an amount less than about 2 percent by weight. 
 
 
     
     
       2. The photocatalytic material as claimed in  claim 1 , wherein the TiO 2  is doped with at least one metal. 
     
     
       3. The photocatalytic material as claimed in  claim 2 , wherein the metal dopant is Platinum (Pt). 
     
     
       4. The photocatalytic material as claimed in  claim 2 , wherein the dopant is at least one selected from the group consisting of Boron-Cerium, Iron-Zinc, and Silver. 
     
     
       5. The photocatalytic material as claimed in  claim 1 , wherein the TiO 2  is doped with Nitrogen. 
     
     
       6. The photocatalytic material as claimed in  claim 1 , wherein the TiO 2  substrate is in anatase phase. 
     
     
       7. The photocatalytic material as claimed in  claim 1 , wherein the polymeric adhesive is a water soluble liquid phase adhesive. 
     
     
       8. The photocatalytic material as claimed in  claim 1 , wherein the dopant is Nitrogen (N). 
     
     
       9. The photocatalytic material as claimed in  claim 1 , wherein the TiO 2  nano rods have a particle size in a range of 40 nanometers to 80 nanometers. 
     
     
       10. An air purifying article comprising:
 a base element; and 
 a photocatalytic material comprising:
 a doped TiO 2  substrate capable of exhibiting photo catalytic behavior on being exposed to visible light, the doped TiO 2  substrate being in a form of TiO 2  nano rods, and 
 a polymeric adhesive that enhances an adhering property of the photocatalytic material capable of being adhered to the base element, wherein the polymeric adhesive comprises:
 an acrylic copolymer added in an amount in range of about 55 percent by weight to about 65 percent by weight, 
 calcium carbonate added in an amount in a range of about 25 percent by weight to about 40 percent by weight, and 
 propylene glycol added in an amount less than about 2 percent by weight. 
 
 
 
     
     
       11. The air purifying article as claimed in  claim 10 , wherein the base element is a CFL lamp. 
     
     
       12. The air purifying article as claimed in  claim 10 , wherein the base element comprises a member selected from the group consisting of a wooden material, a paper sheet, a polymer sheet, a ceramic fiber nonwoven fabric, and a plastic resin material. 
     
     
       13. The air purifying article as claimed in  claim 10 , wherein the TiO 2  is doped with Platinum (Pt). 
     
     
       14. The air purifying article as claimed in  claim 10 , wherein the TiO 2  substrate is in anatase phase. 
     
     
       15. The air purifying article as claimed in  claim 10 , wherein the polymeric adhesive is a water soluble liquid phase adhesive. 
     
     
       16. The air purifying article as claimed in  claim 10 , wherein the TiO 2  nano rods have a particle size in a range of 40 nanometers to 80 nanometers. 
     
     
       17. A photocoat sheet comprising:
 a base sheet; and 
 a photocatalytic material coated on the base sheet, the photocatalytic material comprising:
 a doped TiO 2  substrate capable of exhibiting photo catalytic behavior on being exposed to visible light, the doped TiO 2  substrate being in a form of TiO 2  nano rods, and 
 a polymeric adhesive that enhances an adhering property of the photocatalytic material capable of being adhered to the base sheet, wherein the polymeric adhesive comprises:
 an acrylic copolymer added in an amount in a range of about 55 percent by weight to about 65 percent by weight, 
 calcium carbonate added in an amount in a range of about 25 percent by weight to about 40 percent by weight, and 
 propylene glycol added in an amount less than about 2 percent by weight. 
 
 
 
     
     
       18. The photocoat sheet as claimed in  claim 17 , wherein the TiO 2  substrate is in anatase phase. 
     
     
       19. The photocoat sheet as claimed in  claim 17 , wherein the TiO 2  is doped with at least one metal. 
     
     
       20. The photocoat sheet as claimed in  claim 19 , wherein the metal dopant is Platinum (Pt). 
     
     
       21. The photocoat sheet as claimed in  claim 19 , wherein the dopant is at least one selected from the group consisting of Boron-Cerium, Iron-Zinc, and Silver. 
     
     
       22. The photocoat sheet as claimed in  claim 17 , wherein the TiO 2  is doped with Nitrogen. 
     
     
       23. The photocoat sheet as claimed in  claim 17 , wherein the TiO 2  nano rods have a particle size in a range of 40 nanometers to 80 nanometers.